Two-dimensional membranes are materials with a thickness on an atomic scale. Potential applications of two-dimensional membranes are widespread, including their use in filtration, barrier, and separation devices. Due to their atomic-level thickness, however, two-dimensional membranes often need to be disposed onto a support substrate to provide the needed mechanical support for its intended use. In addition, the support substrate may provide enhanced biocompability and/or easier device integration to the membrane structure.
When a two-dimensional membrane is applied to a support substrate, a large fraction of the pores present in the two-dimensional membrane do not overlap with the passages present in the support substrate. Thus, fluid may only flow through those pores that overlap with the support substrate passages. Those pores that do not overlap with the support substrate passages are not utilized, resulting in low overall pore utilization in the membrane. In many cases, the overall pore utilization for these structures can be as low as 5%, leading to a lower overall fluid flow through the two-dimensional membrane structure.
To increase flow through the two-dimensional membrane structure and to increase overall pore utilization, one method may be to increase the density of pores in the two-dimensional membrane such that the amount of pores that overlap with the support substrate channels is increased. However, increasing the density of pores in the membrane may add to the mechanical strain on the two-dimensional membrane and may make transferability of large-scale membranes (e.g., >1 cm2) to the support substrate difficult.